/**
 * Created by wangyy on 2016/12/26.
 */
'use strict';
class NumberAnimate {

  constructor(opt) {
    let def = {
      from:50,//开始时的数字
      speed:2000,// 总时间
      refreshTime:100,// 刷新一次的时间
      decimals:2,// 小数点后的位数，小数做四舍五入
      onUpdate:function(){}, // 更新时回调函数
      onComplete:function(){} // 完成时回调函数
    };
    this.tempValue = 0;//累加变量值
    this.opt = Object.assign(def,opt);//assign传入配置参数
    this.loopCount = 0;//循环次数计数
    this.loops = Math.ceil(this.opt.speed/this.opt.refreshTime);//数字累加次数
    this.increment = (this.opt.from/this.loops);//每次累加的值
    this.interval = null;//计时器对象
    this.init();
  }
  init(){
    this.interval = setInterval(()=>{this.updateTimer();},this.opt.refreshTime);
  }

  updateTimer(){
        
    this.loopCount++;
    this.tempValue = this.formatFloat(this.tempValue,this.increment).toFixed(this.opt.decimals);
    if(this.loopCount >= this.loops){
      clearInterval(this.interval);
      this.tempValue = this.opt.from;
      this.opt.onComplete();
    }
    this.opt.onUpdate();
  }
  //解决0.1+0.2不等于0.3的小数累加精度问题
  formatFloat(num1, num2) {
    let baseNum, baseNum1, baseNum2;
    try {
      baseNum1 = num1.toString().split(".")[1].length;
    } catch (e) {
      baseNum1 = 0;
    }
    try {
      baseNum2 = num2.toString().split(".")[1].length;
    } catch (e) {
      baseNum2 = 0;
    }
    baseNum = Math.pow(10, Math.max(baseNum1, baseNum2));
    return (num1 * baseNum + num2 * baseNum) / baseNum;
  }
}
export default  NumberAnimate;





